Friday, 13 May 2016

When we
first moved to our rural property in East Gippsland in 1976 there were no Bell
Birds. We now have a colony that has been here for about 15 years. A long-time
local told me that there used to be Bell Birds on the river for many years
however they were either wiped out or moved during the disastrous 1965 fires. It
took 35 years for a new colony to establish after the fires. The new colony has
increased in size over the past 15 years and while the area they occupy has
expanded, the location has not changed even though there is plenty of suitable
habitat along the river.

The colony
is located on the Nicholson River in a tall stand of dominant Manna Gums (E viminalis) and a smaller number of closely
associated River Red Gum (E tereticornis),
Apple Box (E bridgesiana) and Coast Grey Box (E bosistoana).

The Bell
Miner (Manorina melannophrys) is a
honeyeater. The Manorina genus includes three other species, the Noisy,
Yellow-throated and Black-eared Miners. Like their cousins Bell Miners are
colonial birds and aggressively defend territory however the Bell Miner is
unique in that each colony occupies a relatively small well defined area where
it feeds more or less exclusively on sugar produced by sap sucking insects
called psyllids. The white crystalline structures produced by the psyllids are
known as lerp.

Bell
Miner, adult males and females look the same, the red triangle behind the eye
is olive in juveniles.

Tall
Manna Gums near the centre of the Bell Bird colony’s area.

Bell Miners
are well known birds in southeast Australia from Melbourne in the south to around
Gympie in SE Queensland in the north. They are generally confined to the east
side of the Dividing Range. Their loud bell like calls are distinctive and
easily recognised however seeing the birds, even with binoculars, can be
difficult even when there are large numbers calling close by. Their
olive-green-yellow plumage blends in well with the eucalypt canopies they
occupy.

Much has
been written about Bell Miners so I will not include more details in this post
but instead refer you the the following excellent blog posts:

Sunday, 1 May 2016

We have
been fortunate to have a resident male Satin Bowerbird(Ptilonorhynchus(1) violaceus violaceus), including a
bower, the male’s courtship display arena, continuously in our garden for about
10 years now.

Mature
male Satin Bowerbird at bower.

Over the 10
years there have been at least six bowers that we know of, each constructed and
decorated in a separate location with only one bower in the garden at a time.
So it seems only one dominant male at a time is in charge of our garden.

As the
males only reach the fully blue mature stage at age 7 and probably only live on
average to about age 10 or 11 years, we have no doubt had a number of dominant
blue males over the 10 years.

Each bower
is dismantled as the new bower is constructed and the precious blue objects are
moved to the new location.

Male bower
birds are great thieves so the blue objects are continually changing at a bower
as some items are stolen and new ones turn up - some of these stolen and some
newly found. The objects include blue plastics of various origins, however blue
bottle tops and straws are common and Crimson Rosella blue tail feathers are
also common. A few yellow objects are included, often flowers, but sometimes we
have found Sulphur-crested Cockatoo crest feathers at bowers in our garden.

This is the last bower before the one featured in this post. It has now been
completely removed including blue objects.

The number
of blue objects at the new bower is less than are seen in the photo above of
the old bower so I am assuming some have been taken/stolen by other males.

The blue
objects match the colour of the mature male’s plumage, though, depending on the
amount and angle of the light, the plumage can vary from blue to black. The
blue objects also match the vivid blue eyes of the females and immature males.
The mature fully blue males have lilac coloured eyes (see photos).

While the
activity at the bower is at a peak during the breeding season the bower is
maintained throughout the year. The bower in this post was moved to this
location over the past couple of weeks and is still being refined with new
sticks added and sticks in place adjusted and painted. Even though it is autumn
and the breeding season is over there is still plenty of display activity at
the bower as the photos in this post show.

I was
surprised to observe an immature male at the bower busily adding and adjusting
sticks and painting the inside of the bower. The immature male also displayed
and danced around the bower with blue objects held in its bill while another
immature male looked on. The mature blue male was not present.

Immature male Satin Bowerbird. Note the green throat and breast with fine white
spots and streaks. Also note the dark grey bill is just starting to turn a
light colour at the tip indicating this male is about 3 to 4 years old.

The
immature male spent 15 minutes or so adding and adjusting sticks at the bower.

This
stick looks to be too short and crooked for the bower walls?

The bird
was busy moving in and out of the bower.

A
brief pause from bower work for a scratch.

The
green birds are very attractive. This photo has not been cropped - I was very
close, concealed in a chair hide using only a 300mm focal length lens.

The
immature male took a break from bower work to put on a performance with a piece
of blue plastic.

The
display involves jumps and wing and tail movements while making various calls
and buzzing sounds. Another immature male watched on.

The
under tail feathers are very attractive – I am not sure what purpose such
attractive feathers in this location serve given the females selecting mates
are looking at all blue males?

A
little later the blue plastic was discarded and a dry brown faecal pellet, or
perhaps it is an insect larva case, was taken up and the display continued.

The
display included a variety of moves including hops, side jumps and sudden wing
movements.

The
display continued.

In an
observation session a couple of hours later when the adult blue male was
present, two immature males were also at the bower. One of the immature males
stood motionless inside the bower, as a female would, while the mature male
commanded the display area and put on a performance with dance, a variety of
calls and blue objects held in its bill.

The
magnificent mature blue male arrived at the bower and the immature males
adopted a subservient stance.

Note
the lilac coloured eyes of the mature male, the creamy white bill and bill
feathers.

This
immature male appeared to adopt the role of a female at the bower in the mature
male’s presence?

The
immature male stood in the bower while the mature male moved about the display
arena.

The
mature male appeared larger than the immature males?

It would
seem that young males practise bower construction at a mature male’s bower and
also learn to display in preparation for the day when they reach maturity and
build their own bower. The mature male in command of the bower, the owner,
seemed to tolerate the presence of the immature males. I suspect this may not
be the case during the breeding season when receptive females are visiting
bowers.

The Satin Bowerbird and other species of this genus have a small patch of
feathers extending from the forehead down over the root of the bill which gives
the head and bill when viewed from some angles a rather unique shape – see
photos.

Australia
is fortunate to have 8 species of bowerbirds with 5 species in the Ptilonorhynchus genus. This list of
Bowerbird species is copied from the BirdLife Australia working list: